The Linear MHD workflow is
integrated with ElVis. The user interface enables you to:
1. Select a data source,
retrieve, and display data.
1.1 The LMHD Workflow
2. Refine the equilibrium.
3. Run an LMHD program, such as Pest, Pest1, Pest2,
Pest3, Balloon, or M3D-C1.
4. Display results from different runs.
5. Manage runs through the Run History table.
To start a work session, run ElVis and go to: Desktop
--> Linear MHD...
2. Data Sources
The data sources consist of EFIT01 from NSTX, Plasma State
files, or a TRANSP run.
In the Data Source panel go to the Shot tab to specify source
data from EFIT. Enter the NSTX shot number and click on
Get Times. This will return a list of times when EFIT has
been run. Click on a time to use and click Retrieve.
This will get a Plasma State file for the specified time and
display 4 graphs. The entire Plasma State is in the graph
window so additional plots can be constructed. The data is
store in the run directory shown as Next Run ID. Text
output from the retrieval is shown in the Status panel.
The Pest program works with 1 or more EFIT times as the source
data. All other codes work with source data from
just 1 EFIT time.
Figure 1 - Retrieve source data
from available EFIT times. Time indices 353 and 385 have
been selected for a Pest run. All other programs start
with just 1 time index.
2.2 TRANSP Run
In the Data Source panel go to the TRANSP Run tab. Enter
the Run ID, time of interest, and time average. Click on
Retrieve to extract a plasma state for the specified time.
A graph window is displayed with 6 graphs. The entire
plasma state is in the window so additional plots can be
Figure 2 - Retrieve source data
from a TRANSP run.
The data for the TRANSP run can be examined in RPLOT within
ElVis by clicking on Plot. This will bring up an RPLOT
session within ElVis. You can enter RPLOT commands or
scripts to plot graphs from the run.
Figure 3 - Running RPLOT within
ElVis to examine data from a TRANSP run.
2.3 Importing Files
Existing files can be imported as the source to an LMHD
run. Select the type of file to import as either GEQ file,
Plasma State file, EQDSKA file, or a Refined Equilibrium (eqb1)
file. Enter the name of the file in the text field and
Figure 4 - Importing a Plasma
The LMHD programs work from a refined equilibrium. The
workflow will run JSolver to produce an eqb1 file and an
eqdsk.cdf file in the run directory. Click on Refine
Equilibrium to run JSolver. Two graphs from the resulting
plasma state will be displayed and the text output will be shown
in the Status panel.
Figure 5 - Equilibrium
refinement computed by JSolver.
An LMHD program can be run after the equilibrium refinement
stage. Select the program by clicking on one of the tabs
along the left edge of the Run panel. Then click the Run
button. M3D has 4 additional menus. The Sim tab
contains the name list where the value of each parameter can be
set for M3D-C1. The PETSC tab has the name list for the
PETSC portion of the simulation. The CPUs tab lets you
control the number of cpus assigned to the run. The Job
tab has fields for setting the maximum amount of CPU time and
selecting the batch queue where the job will be run on hopper at
Nersc. Click the Run M3D button to submit a job. You
must have an account at Nersc and a batch allocation in order to